You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so , join our community today!

If you have any problems with the registration process or your account login, please contact us.

pixel aspect ratio correction; .jpg glitch

microsoft.public.windows.vista.music pictures video

Vista seems to be radically distorting .jpegs.
This issue is inconsistent. I have many hundreds of photos stored as .jpgs
and they seem to dsplay fine, as thumbnails, previews, or when opened into
photoshop. But I also have 100's of illustrations and sketches, stored in
..jpg format, and many--not all [lets say: 1 in 5] are being viewed in Vista
thumbnails and previews as squashed in the horizontal axis to just a few
pixels wide.

When they are opened into photoshop, equally distorted (although, the
thumbnail and preview of the image in Photoshops Browser looks correct), I
get a message that says:"Pixel aspect ratio correction is for preview
purposes only. Turn it off for maximum image quality."

I never play with pixel aspect correction. All these images had square
pixels when they were created, and do so currently, on the computer
(WinXPpro) that they came from.

So, how does this happen, and how can I fix it, in Vista?-- without browsing
for and opening every single image in photoshop and correcting it and
resaving it.
--
Rob
Lead Artist

Vista seems to be radically distorting .jpegs.
This issue is inconsistent. I have many hundreds of photos stored as .jpgs
and they seem to dsplay fine, as thumbnails, previews, or when opened into
photoshop. But I also have 100's of illustrations and sketches, stored in
..jpg format, and many--not all [lets say: 1 in 5] are being viewed in Vista
thumbnails and previews as squashed in the horizontal axis to just a few
pixels wide.

When they are opened into photoshop, equally distorted (although, the
thumbnail and preview of the image in Photoshops Browser looks correct), I
get a message that says:"Pixel aspect ratio correction is for preview
purposes only. Turn it off for maximum image quality."

I never play with pixel aspect correction. All these images had square
pixels when they were created, and do so currently, on the computer
(WinXPpro) that they came from.

So, how does this happen, and how can I fix it, in Vista?-- without browsing
for and opening every single image in photoshop and correcting it and
resaving it.
--
Rob
Lead Artist

I found the problem... and some solutions,

Problem:
If and whenever Window Photo Gallery (WPG) modifies a JPG I don't know exactly what but it changes the EXIF metadata subsequent editing of the file in another editor causes this resolution error.

Id don't know how the EXIF data gets corrupt but my scenario is scanning in photos that have no EXIF data. If I allow WPG to rotate the file for a portrait shot then subsequent editing corrupts the EXIF data... but only by WPG. I can still open the file in other editors.
but now the EXIF data in Vista says something like 166450x82 dpi for the vertical and horizontal resolutions rather then the actual 96x96 dpi.

The reason Vista thumbnail viewer also has this problem is because WPG is the display engine used by Vista OS to render the thumbnails.

Solutions:
This is what I have come up with, (1) don't allow WPG to edit/midofy anything. if in the EXIF metadata Origin:Program name: field, if it says Microsoft Windows Photo Gallery then WPG has already at one time modified the file. If this data field is blank your file should be OK.

If you have the original virgin file, in my case I needed to rotate the file because it was a portrait shot, then rotate the picture in a graphics editor other then WPG, i.e. photoshop or PSPX--what I use. This will prevent the resolution information within the EXIF metadata from being corrupted.

If you don't have the original anymore or if the photo was a download and has be modified by WPG, i.e. the EXIF field Origin:Program name: says "Microsoft Windows Photo Gallery" then try opening the file into a graphics editor that will display the image correctly, then do a screen capture of the image and paste as a new image. I have found a copy and past of the image from within PSPX also copies the EXIF data and whatever in there is corrupting the preview.